Burner and oven



,014 Ken-m BURNER AND OVEN Filed June 19, 1922 Patented June 3%, i325.

MILTON ll-I. KOHN, OF NEVT YORK, N.

BURNER- AND OVEN.

Application filed June 19, 1922. Serial No. 599,346.

To all whom 2'25 may concern.

P36 it known that l, liilnrron M. Kenn, a citizen ot the United States, residing in New York, in the county of New York and State of New York, have invented certain new and useful improvements in Burners and (lvens, of which the following is a specification.

This invention relates to ovens, of the type used by dentists, jewelers and like artizans for raising relatively small quantities of material to a high degree of temperature.

The principal object is to provide a heat retaining chamber suited to be so disposed as to receive and hold substantially all of the heat possible to derive from a burner arranged therebelow.

Another purpose is to produce an oven in which the heat insulating lining is reniovably engaged so that the same may be readily replaced with in interchangeable duplicate.

These and other aims, such as draft control, anc economy in construction, are at tained by the novel design and combination of parts further on described and illustrated in the annexed drai ing, forming part here-' of, and in which Figure l is a partial side elevational, partial sectional view of an embodiment of he invention in operative position.

Figure 2 is a transverse sectional view looking upward on line 22 of Fig. l and drawn to a reduced scale.

Figure 3 is a fragmentary sectional view showin a modification oi the oven structure.

Figure t is a plan view of the removable shutter used in connection with the oven.

igure 5 is a fragmentary sectional view of the upper end of the oven showing the shutter in place thereon.

Stated in general terms, the invention con sists in an appliance particularly designed and adapted for shops, laboratories, etc., where small quantities of material and metals are to be brought to a high degree of heat in a rapid and uniform manner, under perfect control, as in casting dental bridges, inlays, etc, in moulds or investments in dividually formed to suit special requirements. 7

The heat retainer consists of a thin walled, preferably circular metallic casing (leprovided with permanent handles 66 on opposite sides and having a conical upper portion 67 formed into a contracted open neck or band 68 terminating in an outsturned bead G9, the opening thus presented providing for the passage of consumed gases.

The bottom of the casing is shaped to produce an outstanding concavo-convex ring or head 70, in which is received a flat sheet metal, washer-like plate 71 having a raised annular flange 72 at its inner peripheral edge, said upstanding flange encircling the elements 52 of the supporting spider, while the flat horizontal plate 71 rests upon the arm extensions 55.

A resilient wire locking ring 73 is suited to enter the inner portion of the bead 70, maintaining the plate therein, the ring 78 having inturned prongs 74 adapted to be grasped by the lingers in removing the plate 71.

Contained in the casing is a block 75 preferably moulded of non-conducting ma terial, as init'usorial earth, diatomaceous substance or the like, which prevent heat radiation or absorption, maintaining the heat within the central chamber.

This block or lining 75 which may be moulded into any special shape required, is preferably open at the bottom, being removably held between the casing 65 and flange 72 and its upper, open end 76 is preferably slightly smaller in diameter than the opening in the casing throat 68 and can be titted with a removable closure for controlling the circulation of heat in the oven.

The battle or shutter, generally designated by the numeral 77, shown in Fig. 4t, may be used in connection with the chamber, the shutter being composed of two similar levers 78, pivotally connected at 79 and provided with extending operating handles 80.

The main portion of these levers have semi-circular extensions 81 provided with downturned flanges which are adapted to embrace the heading 69 of the oven casing and formed between adjacent edges of the extensions is a small opening 82. However, the elements 77 to 82 inclusive are not claimed as part of this invention nor the shutter device at the top of the casing these elements being old and of well known com mon form.

Any preferred type of flask, container, crucible or other device for the articles or materials to be subjected to the heat may rest upon supports, as the spider arms 52, the same entering between the flanged walls 72 of the oven support and the corrugations on the arms act to hold the container in adjustment during operation.

In the modification, shown in Fig. 3 the casing is continued down as a straight cylinder, the bead omitted and formed on the periphery of the washer plate 71, is an upturned flange 71 fitting the cylinder and held by readily removable screws While the use of a heat retention device is not in itself new, it is believed that none presents, an inner heat insulation lining that can be removed or replaced should injury occur, in the simple but eflicient man- 7 ner presented.

Although I have described my improvements with considerable detail and with respect to certain particular forms of my invention, I do not desire to be limited to such details since many changes and modifications may well be made without departing from the spirit anc scope of my invention in its broadest aspect.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

'1. A heat retainer comprising a casing having a beaded lower edge, a nonconducting lining enterable from the bottom therein, and means partially contained in said beaded edge for removably securing said lining within said casing and means to support the retainer in a plane raised from the supporting surface.

2. A heatretamer comprising a metallic casing, anon-conducting lining engageable 4:. A. heat retainer comprising a metallic casing, a non-conducting lining removably engaged therein, a plate interiorally of said casing on which said lining rests said plate having a circular opening, an upstanding'flange on the inner edge of said .plate in contact with the interior of said lining, and spring means for confining said plate in said casing. v

5. A heat retainer comprising a metallic casing having a conical upper portion containing an axial opening, a heading formed at the bottom of the casing, a non-conducting lining suited to said casing, a plate in said beading, said plate having a cent al opening, a raised edge surrounding the opening, .said plate retaining the lining, a spring wire ring in said beading acting to lock said plate therewithin, and means formed with said ring whereby it can be removed.

6. In combination with a burner, of a heat retainer supported above the flame issuing from said burner, a heatinsulating lining in said heat retainer, a band interjacent the lower portion of said lining, afiangeextending outwardly from said band, said flange resting on the supports, and means normally contained in the lower edge of the heat retaining shell to engage said flange.

7 In an oven having a cylindrical casing and a conical upper portion, a lining comprised of infusorial earth moulded to present an. integral body, loosely fitting said casing,including its upper portion, and a supporttor said lining, said support having a part extending into said lining to guide the same.

S. In a temperature retaining device, the combinationwith a metallic casing, of an insulating chamber composed of infusorial earth or similar diatomaceous material and cement, said chamberbeing moulded under pressure and having a vent at the top, a metallic support to secure said chamber in the casing, said support also acting as a guide for the chamber, and a spring ring to removably retain said support in the casing, In testimony whereof I have signed my name to this application.

MILTON M. KOHN. 

